1. Field of the Invention
The present invention generally relates to a method and an assembly for vehicle thermal management and to a vehicle which incorporates the method and assembly and more particularly, to a method and an assembly which measures the temperature of a vehicular component or assembly in order to create or select a thermal change function or thermal gradient, which uses the thermal change function or thermal gradient to create a time to temperature value which is approximately equal to the time in which a predetermined maximum operating temperature will be reached by the vehicular component or assembly, and which performs a certain action in response to the approximated time to temperature value.
2. Background of the Invention
A motor vehicle includes many selectively movable and interconnected components and assemblies which are adapted to operate within a certain respective temperature range and which are respectively associated with a maximum operating temperature that should not be exceeded.
Current thermal management strategies utilize temperature sensors for providing positive indications only when the respective temperature of the various monitored assemblies and components actually exceeds a certain respective threshold value.
While the foregoing information is somewhat useful to the operator of the vehicle, preemptive action is often not possible in advance of the actual occurrence of this undesirable situation. Accordingly, once the positive indication is provided, the operator is required to stop or immediately disable the vehicle even if it is not very desirable to do so (e.g., such as when a hybrid-electric vehicle is positioned upon the side of a hill or mountain), in order to cool the components.
Further, conventional strategies require an operator of the vehicle to perform some action and do not automatically or dynamically (e.g., without operator intervention) modify the operation of the vehicle in order to preemptively regulate the temperature of the monitored items in order to correct or compensate for such an undesired operation, while concomitantly reducing the likelihood that an item will meet/exceed its maximum operating temperature.
The present invention overcomes these drawbacks in a new and novel fashion and controls the operation of certain vehicular items, such as and without limitation a drivetrain or transmission assembly, by the use of active or dynamic preemptive regulation.
A method and an apparatus which overcomes some or all of the various previously delineated drawbacks of prior vehicular operating strategies and techniques. Advantageously, the method and assembly dynamically and preemptively provides a warning to a vehicular operator that one or more vehicular items may become undesirably heated. The method and assembly of the present invention automatically and dynamically regulates the operating temperature of a vehicular item, thereby substantially reducing the likelihood of undesired operation.
In accordance with a first aspect of the present invention, a thermal control assembly is provided which determines whether a certain portion of a vehicle which is selectively operable at a certain speed will exceed a certain operating temperature within a certain period of time and which reduces the likelihood of the portion of the vehicle exceeding the certain operating temperature. Particularly, the assembly includes at least one sensor which is coupled to the certain portion of the vehicle and which provides a first temperature of the certain portion of the vehicle at a first time and a second temperature of the certain portion of the vehicle at a second time, and a controller which is coupled to the at least one sensor, which receives the first and second temperatures, which uses the first and second temperatures to calculate a time period, and which decreases the certain speed of the portion of the vehicle when the calculated time period is less then the certain period of time.
In accordance with another aspect of the present invention, a vehicle is provided having: a transmission assembly having a certain maximum allowable operating temperature and being operable at a certain speed; at least one sensor which is coupled to the transmission assembly, which measures a first, a second, and a third temperature of the transmission assembly; and a controller which is coupled to the at least one sensor and to the transmission assembly, which receives the first, second, and third temperatures, which storably contains a thermal gradient function, which uses the second and third temperatures and the thermal gradient function to ascertain a time in which the transmission assembly will exceed the certain maximum allowable operating temperature only when the first temperature exceeds a certain value, which storably contains a time value, which compares the calculated time to the time value and, based upon this comparison, selectively reduces the speed of the transmission assembly, effective to reduce the likelihood of the transmission assembly from having a temperature which exceeds the maximum allowable operating temperature.